An essay is a mix of art and science (this means that it uses creative, literary and logical elements to handle ideas). This dual essence in an essay (some will use this to say it’s a hybrid genre) is the origin of its power and difficulty. Because it’s a centaur, half one thing and half another thing, the essay can deal with all areas of knowledge and all topics. However, no matter what topic is chosen, the essay needs some “finesse” in its writing, so that it’s highly literary.
An essay is not a commentary (writing about an opinion), but is rather a meditation, and it’s almost always derived from other people’s meditations (these people don’t necessarily have to be mentioned explicitly, although they’re usually mentioned in the footnotes or in the references). This is why the essay depends more on judgment and arguments (they’re not free opinions). The essay has to support the ideas. Better yet, the quality of an essay is measured through the quality of its ideas, the way in which they’re communicated, faced and taken into consideration. If there are no strong arguments, if they haven’t been developed beforehand, the essay becomes merely an assumption.
An essay reasons. It’s a complete discourse. Good essays are linked in a coherent manner. It’s not about putting one idea after the other, because the addition of ideas does not constitute a good essay: you have to weave them in an organized manner, and you have to organize the ideas in a hierarchy, weighing them (let’s remember that ‘essay’ comes from ‘exagium’ which means, precisely, “weighing”). If there’s no logic in the composition of an essay, it will be difficult to get acceptable results, just as in music. This is why it’s important to make a plan, a map, a sketch – it works as a guide to write the essay.
Just like a discourse, the essay requires a good usage of connecting elements (you have to keep a reserve of them). The connecting elements are like the hinges, the links that are necessary for the essay to not seem to be lacking cohesion. There are relationship connectors, consequence connectors and causality connectors. There are also connectors to summarize or emphasize. And, next to the connectors, it’s essential to have a perfect command of punctuation. Thanks to the comma and the semicolon (one of the most difficult-to-use punctuation signs), and thanks to the period, this is how the essay breathes, has a rhythm, a life. The inadequate or proper use of punctuation signs is what determines if our essay is monotonous or light, interesting or boring, flexible or tedious.